2018 MAZDA CX-9 Complaints

Bought car new in 2018. At 72,600 observed coolant leaking from backside of motor. Carried to Classic Mazda of Texarkana,TX for diagnostic test. Has a cracked cylinder head.Mazda refused to pay to fix or assume any responsibility for the design flaw. Turbo charger is too close to the cylinder head causing heat issues over time resulting in cracked head/coolant leak.

Coolant leak at cylinder head. It is available for inspection. Driving on the highway and the car overheating light came on. Yes it has been reproduced and diagnosed as part of the TSB 01-013/21. No warnings, no notice of leaks before this happened. Noticed this in January - and thought it was just a one off and had the coolant topped off. Nothing happened until a month later that is when I took it to the mazda dealer. Safety issue as no one knows about it until their light comes on and they take it to the dealer to look at. Having this happen in the middle of nowhere on a highway with three small kids is a nightmare. This issue needs to be investigated. It is definitely a safety issue. It is shocking to know that Mazda has known about this for a couple years now based on the date of the TSB. A letter, at the very least, should have been sent out to all owners. Instead they let us all sit with a ticking time bomb that will be cost prohibitive to fix.

The vehicle has a cracked cylinder head as a result of stress put on the block from a bad exhaust manifold design. This is a known issue to Mazda and service bulletin was sent out to all their dealerships in 2021. Mazda only offered to pay a very small portion of the repair and puts the rest of the cost on the customer. Luckily I caught the issue early but this could have been dangerous if the car overheated and the engine failed on the highway. There are countless other stories of consumers having the same issue with the CX-9 and CX-5 of the same year. Many resulting in engine failure.

I own a 2018 Mazda CX – 9 with only 53,300 miles. I noticed something was wrong with my engine and had no idea what the issue was. My car would not shut off immediately when I turned it off and the fan was on super high speed. The day before my appointment with my mechanic, the engine light turned on. I was stuck in a parking lot and a friend suggested I use his car to go buy coolant just in case it was needed. Sure enough, I was completely out of coolant. When my mechanic inspected the car he told me I had a coolant leak and suggested I take it to the dealer as they would know immediately what the problem was. I started researching to see if this was a defect and sure enough, Mazda has been aware of the defect with the cylinder head (TSB) not supporting the turbo of the engine causing it to crack and mix with the engine oil in various models for years, yet continue to sell cars with this known defect. I understand that it may not be life threatening yet! But it could have been should my engine had blown while I was on the freeway causing a horrific accident. How are they allowed to continue manufacturing and sell cars with a known issue for years and not even be reuqired to make a recall to have the part replaced with a stronger one? This is issue is happening to 100's of customers worldwide. This is something that should be investigated.

Infotainment screen has spider cracking from faulty screen when manufactured. Open TSB stating this and Mazda refuses to replace under warranty after 5 months of owning vehicle, spider cracks got worse this year. When i got more spider cracks i contacted mazda support since the first time I contacted a local dealer. Mazda support denied replacement because “ i do not get my car serviced through mazda”, this screen issue has nothing to do with a car being serviced. This is a safety issue as you can not see parts of the screen and will only get worse and make the whole screen inoperable when using navigation.

Coolant leak into cylinder head, resulting in overheating and blown head gasket. Repair cost was $7k to resurface cylinder head and replace gasket. Repair did not fix issue, likely due to unseen cracks or warping to cylinder head. Will require rework, likely entire engine replacement, as the defect cannot be corrected.

The infotainment system screen has developed several cracks in the upper left-hand corner of the screen. Often time these cracks look like spiderwebs or frost --it's commonly referred to as "spider cracking." This is the second time my vehicle has had this issue. At the present time, the cracks are contained to the upper left-hand corner of the screen, but they are getting larger. The vehicle has been inspected by my local MAZDA dealership and I'm awaiting a resolution. As I understand, this is a known issue with 2016-2017 model years and a TSB has been issued for these years. MAZDA should extend the TSB to 2018 and beyond.

The main infotainment display randomly exhibited "spider cracking" which obstructs the view of the material being displayed within the screen. It is unsafe because the operator is unable to see maps, time, locations, controls, reverse cameras, etc. All of these are displayed in the screen and, due to the manufacturing defect, the operator is distracted by straining to see what is displayed behind the cracking. This is a well documented issue plaguing Mazda vehicles. Mazda has admitted it as defective, and are fixing the problem in the 2016-17 models. However, the 2018 model (which has the same screen as the 2016-17) is being refused. The fix needs to be extended to the 2018 model and beyond since it iw clear this it is still a widespread issue. It is well documented that once the cracking starts, it quickly spreads to the entire screen if not repaired, causing even more danger to the operator who will be distracted while attempting to see the display behind the screen.

Driving the car home from work, the engine temperature gauge started to go up high. I added coolant that same night. Went to the dealership for a check up. I was told the coolant was coming out from the back of the engine and will need to partial repair the engine. Only 75k miles in the engine and that was an estimate cause I could need a brand new engine. Now I’m stranded with out a car waiting for a response. MAZDA should do a recall regarding that issue cause I’ve seen a lot of CX9s have the same issue. THATS NOT GOOD FOR RELIABILITY.

After owning this used vehicle for about 11 months, the engine temperature gauge indicated the car was running hot - about 240 degrees. After inspecting the vehicle at home, we added coolant to the system. This helped maintain engine temperature temporarily, but we noted over the next several weeks that the coolant was dropping rapidly. After inspection by a Mazda dealer, it was concluded that the cylinder head needed replacing.